Phosphatidylinositol 3-kinases (PI3Ks) comprise a family of lipid kinases that catalyze the transfer of phosphate to the D-3′ position of inositol lipids to produce phosphoinositol-3-phosphate (PIP), phosphoinositol-3,4-diphosphate (PIP2) and phosphoinositol-3,4,5-triphosphate (PIP3) that, in turn, act as second messengers in signaling cascades by docking proteins containing pleckstrin-homology, FYVE, Phox and other phospholipid-binding domains into a variety of signaling complexes often at the plasma membrane (Vanhaesebroeck et al., Annu. Rev. Biochem 70:535 (2001); Katso et al., Annu. Rev. Cell Dev. Biol. 17:615 (2001)). Of the two Class 1 PI3Ks, Class 1A PI3Ks are heterodimers composed of a catalytic p110 subunit (α, β, δ isoforms) constitutively associated with a regulatory subunit that can be p85α, p55α, p50α, p85β or p55γ. The Class 1B sub-class has one family member, a heterodimer composed of a catalytic p110γ subunit associated with one of two regulatory subunits, p101 or p84 (Fruman et al., Annu Rev. Biochem. 67:481 (1998); Suire et al., Curr. Biol. 15:566 (2005)). The modular domains of the p85/55/50 subunits include Src Homology (SH2) domains that bind phosphotyrosine residues in a specific sequence context on activated receptor and cytoplasmic tyrosine kinases, resulting in activation and localization of Class 1A PI3Ks. Class 1B PI3K is activated directly by G protein-coupled receptors that bind a diverse repertoire of peptide and non-peptide ligands (Stephens et al., Cell 89:105 (1997); Katso et al., Annu. Rev. Cell Dev. Biol. 17:615-675 (2001)). Consequently, the resultant phospholipid products of class I PI3K link upstream receptors with downstream cellular activities including proliferation, survival, chemotaxis, cellular trafficking, motility, metabolism, inflammatory and allergic responses, transcription and translation (Cantley et al., Cell 64:281 (1991); Escobedo and Williams, Nature 335:85 (1988); Fantl et al., Cell 69:413 (1992)).
In many cases, PIP2 and PIP3 recruit Akt, the product of the human homologue of the viral oncogene v-Akt, to the plasma membrane where it acts as a nodal point for many intracellular signaling pathways important for growth and survival (Fantl et al., Cell 69:413-423(1992); Bader et al., Nature Rev. Cancer 5:921 (2005); Vivanco and Sawyer, Nature Rev. Cancer 2:489 (2002)). Aberrant regulation of PI3K, which often increases survival through Akt activation, is one of the most prevalent events in human cancer and has been shown to occur at multiple levels. The tumor suppressor gene PTEN, which dephosphorylates phosphoinositides at the 3′ position of the inositol ring and in so doing antagonizes PI3K activity, is functionally deleted in a variety of tumors. In other tumors, the genes for the p110α isoform, PIK3CA, and for Akt are amplified and increased protein expression of their gene products has been demonstrated in several human cancers.
Furthermore, mutations and translocation of p85α that serve to up-regulate the p85-p110 complex have been described in human cancers. Finally, somatic missense mutations in PIK3CA that activate downstream signaling pathways have been described at significant frequencies in a wide diversity of human cancers (Kang et al., Proc. Natl. Acad. Sci. USA 102:802 (2005); Samuels et al., Science 304:554 (2004); Samuels et al., Cancer Cell 7:561-573 (2005)). These observations show that deregulation of phosphoinositol-3 kinase and the upstream and downstream components of this signaling pathway is one of the most common deregulations associated with human cancers and proliferative diseases (Parsons et al., Nature 436:792 (2005); Hennessey et al., Nature Rev. Drug Disc. 4:988-1004 (2005)).
It has been found that the 2-carboxamide cycloamino urea derivatives of the Formula (I) given below have advantageous pharmacological properties and inhibit, for example, PI3K (phosphatidylinositol 3-kinase). In particular, these compounds preferably show an improved selectivity for PI3K alpha with respect to beta and/or, delta and/or gamma subtypes. Hence, the compounds of Formula (I) are suitable, for example, to be used in the treatment of diseases depending on PI3 kinases (in particular PI3K alpha, such as those showing overexpression or amplification of PI3K alpha or somatic mutation of PIK3CA), especially proliferative diseases such as tumor diseases and leukaemias.
Further, these compounds preferably show improved metabolic stability and hence reduced clearance, leading to improved pharmacokinetic profiles.
Mutations in various Ras GTPases and the B-RAF kinase have been identified that can lead to sustained and constitutive activation of the MAPK pathway, ultimately resulting in increased cell division and survival. As a consequence of this, these mutations have been strongly linked with the establishment, development, and progression of a wide range of human cancers. The biological role of the Raf kinases, and specifically that of B-RAF, in signal transduction is described in Davies, H., et al., Nature (2002) 9:1-6; Garnett, M. J. & Marais, R., Cancer Cell (2004) 6:313-319; Zebisch, A. & Troppmair, J., Cell. Mol. Life Sci. (2006) 63:1314-1330; Midgley, R. S. & Kerr, D. J., Crit. Rev. Onc/Hematol. (2002) 44:109-120; Smith, R. A., et al., Curr. Top. Med. Chem. (2006) 6:1071-1089; and Downward, J., Nat. Rev. Cancer (2003) 3:11-22.
Naturally occurring mutations of the B-RAF kinase that activate MAPK pathway signaling have been found in a large percentage of human melanomas (Davies (2002) supra) and thyroid cancers (Cohen et al J. Nat. Cancer Inst. (2003) 95(8) 625-627 and Kimura et al Cancer Res. (2003) 63(7) 1454-1457), as well as at lower, but still significant, frequencies in the following:
Barret's adenocarcinoma (Garnett et al., Cancer Cell (2004) 6 313-319 and Sommerer et al Oncogene (2004) 23(2) 554-558), billiary tract carcinomas (Zebisch et al., Cell. Mol. Life Sci. (2006) 63 1314-1330), breast cancer (Davies (2002) supra), cervical cancer (Moreno-Bueno et al Clin. Cancer Res. (2006) 12(12) 3865-3866), cholangiocarcinoma (Tannapfel et al Gut (2003) 52(5) 706-712), central nervous system tumors including primary CNS tumors such as glioblastomas, astrocytomas and ependymomas (Knobbe et al Acta Neuropathol. (Berl.) (2004) 108(6) 467-470, Davies (2002) supra, and Garnett et al., Cancer Cell (2004) supra) and secondary CNS tumors (i.e., metastases to the central nervous system of tumors originating outside of the central nervous system), colorectal cancer, including large intestinal colon carcinoma (Yuen et al Cancer Res. (2002) 62(22) 6451-6455, Davies (2002) supra and Zebisch et al., Cell. Mol. Life Sci. (2006), gastric cancer (Lee et al Oncogene (2003) 22(44) 6942-6945), carcinoma of the head and neck including squamous cell carcinoma of the head and neck (Cohen et al J. Nat. Cancer Inst. (2003) 95(8) 625-627 and Weber et al Oncogene (2003) 22(30) 4757-4759), hematologic cancers including leukemias (Garnett et al., Cancer Cell (2004) supra, particularly acute lymphoblastic leukemia (Garnett et al., Cancer Cell (2004) supra and Gustafsson et al Leukemia (2005) 19(2) 310-312), acute myelogenous leukemia (AML) (Lee et al Leukemia (2004) 18(1) 170-172, and Christiansen et al Leukemia (2005) 19(12) 2232-2240), myelodysplastic syndromes (Christiansen et al Leukemia (2005) supra) and chronic myelogenous leukemia (Mizuchi et al Biochem. Biophys. Res. Commun. (2005) 326(3) 645-651); Hodgkin's lymphoma (Figl et al Arch. Dermatol. (2007) 143(4) 495-499), non-Hodgkin's lymphoma (Lee et al Br. J. Cancer (2003) 89(10) 1958-1960), megakaryoblastic leukemia (Eychene et al Oncogene (1995) 10(6) 1159-1165) and multiple myeloma (Ng et al Br. J. Haematol. (2003) 123(4) 637-645), hepatocellular carcinoma (Garnett et al., Cancer Cell (2004), lung cancer (Brose et al Cancer Res. (2002) 62(23) 6997-7000, Cohen et al J. Nat. Cancer Inst. (2003) supra and Davies (2002) supra), including small cell lung cancer (Pardo et al EMBO J. (2006) 25(13) 3078-3088) and non-small cell lung cancer (Davies (2002) supra), ovarian cancer (Russell & McCluggage J. Pathol. (2004) 203(2) 617-619 and Davies (2002) supr), endometrial cancer (Garnett et al., Cancer Cell (2004) supra, and Moreno-Bueno et al Clin. Cancer Res. (2006) supra), pancreatic cancer (Ishimura et al Cancer Lett. (2003) 199(2) 169-173), pituitary adenoma (De Martino et al J. Endocrinol. Invest. (2007) 30(1) RC1-3), prostate cancer (Cho et al Int. J. Cancer (2006) 119(8) 1858-1862), renal cancer (Nagy et al Int. J. Cancer (2003) 106(6) 980-981), sarcoma (Davies (2002) supra), and skin cancers (Rodriguez-Viciana et al Science (2006) 311(5765) 1287-1290 and Davies (2002) supra). Overexpression of c-Raf has been linked to AML (Zebisch et al., Cancer Res. (2006) 66(7) 3401-3408, and Zebisch (Cell. Mol. Life Sci. (2006)) and erythroleukemia (Zebisch et al., Cell. Mol. Life Sci. (2006).
By virtue of the role played by the Raf family kinases in these cancers and exploratory studies with a range of preclinical and therapeutic agents, including one selectively targeted to inhibition of B-RAF kinase activity (King A. J., et al., (2006) Cancer Res. 66:11100-11105), it is generally accepted that inhibitors of one or more Raf family kinases will be useful for the treatment of cancers associated with Raf kinase.
Many cancers, particularly those carrying B-RAF mutation, B-RAF V600E mutation, PIK3CA mutation and/or PIK3CA overexpression are amenable to treatments with, for example, a B-RAF inhibitor. However, in certain cases, the cancers acquire resistance to the chosen therapeutic and ultimately become refractory to treatment.
In spite of numerous treatment options for cancer patients, there remains a need for effective and safe therapeutic agents and a need for their preferential use in combination therapy. In particular, there is a need for effective methods of treating or preventing cancers, especially those cancers that have been resistant and/or refractive to current therapies.